This example uses the matplotlib.pyplot interface to Matplotlib, but WCSAxes
can be used with any of the other ways of using Matplotlib (some examples of which
are given in Initializing axes with world coordinates). For example, using the partially object-oriented
interface, you can do:

In the rest of this documentation we will assume that you have kept a reference
to the axes object, which we will refer to as ax. However, we also note
when something can be done directly with the pyplot interface.

WCSAxes supports a number of advanced plotting options, including the ability to
control which axes to show labels on for which coordinates, overlaying contours
from data with different coordinate systems, overlaying grids for different
coordinate systems, dealing with plotting slices from data with more than two
dimensions, and defining custom (non-rectangular) frames.